Abstract: The invention includes a mechanical scanning feed and a spherical lens antenna system. The mechanical feed includes a waveguide, which has a movable wall assembly that contains a guide slot. The moveable wall portion also includes an end wall that is located proximate to the guide slot to prevent leakage of the propagating energy out of the waveguide. The mechanical feed also includes a drive mechanism, which moves the moveable wall assembly along the waveguide in a direction that is parallel to the direction of propagation of the energy. This allows the guide slot to be positioned at any elevation angle to allow a portion of the propagating energy to exit through the guide slot. This in combination with the waveguide being able to be rotated 360 degrees about the spherical lens provides the antenna system with nearly spherical coverage.

Abstract: A continuous process for the production of poly(trimethylene terephthalate) is disclosed. According to the process, a liquid feed mixture comprising bis-3-hydroxypropyl terephthalate and/or low molecular weight polyesters of 1,3-propanediol and terephthalic acid, the liquid feed mixture having a mole ratio of propylene groups to terephthalate groups of 1.1 to 2.2 is fed to a flasher. A first stream of gaseous by-products is continuously vaporized and removed from the flasher, and a liquid flasher reaction product having a mole ratio of propylene groups to terephthalate groups of less than about 1.5 is continuously withdrawn from the flasher. The liquid flasher reaction product is continuously fed to a prepolymerizer where it is continuously polymerized to form a poly(trimethylene terephthalate) prepolymer and a second stream of gaseous by-products.

Abstract: A phased array antenna system operative to broadcast multiple beams that each include coded data for specific users located within the coverage area of the corresponding beam. An appropriate receiver then receives and decodes a particular beam to extract the specific data for a corresponding user. Multiple users may be assigned to each beam using frequency division or orthogonal code multiplexing, and the user data may be encoded into the beams using frequency shift key or phase shift key encoding. For each coding technique, the encoded antenna control signals are combined into a total gain and total phase shift control signal, which drives a single phase and gain control device for each antenna element. In addition, a single data modulator generates the coding parameters for the entire communication system.

Abstract: A stable partially oriented poly(trimethylene terephthalate) yarn suitable for use in subsequent drawing and/or draw-texturing operations characterized by an elongation to break of at least 110%, and a process for false-twist texturing a partially oriented poly(trimethylene terephthalate) yarn.

Abstract: A process for the continuous production of at least one of bis(3-hydroxypropyl) terephthalate and low molecular weight oligomers of 1,3-propanediol and terephthalic acid is disclosed. According to the process, preheated 1,3-propanediol (about 150° C. to about 200° C.) and preheated lower dialkyl esters of terephthalic acid (about 150° C. to about 220° C.) are combined in a mole ratio of about 1.2:1 to about 2.3:1 and fed to an ester exchange vessel where the mixture undergoes a continuous transesterification reaction. The liquid reaction mixture is continuously heated and mixed, at a temperature of about 215° C. to about 250° C., and a pressure of about 800 mm Hg to about 1,000 mm Hg. Gaseous reaction products are continuously separated from the liquid reaction mixture, and a stream of liquid reaction products containing bis(3-hydoxypropyl) terephthalate and low molecular weight oligomers of 1,3-propanediol and terephthalic acid is continuously removed from a base portion of the ester exchange vessel.

Abstract: A low-profile antenna system to be mounted to a moving vehicle for receiving signals, such as from a Digital Broadcast Satellite, includes a base for mounting to the surface of the vehicle, a platen mounted to the base for rotation, an azimuth drive motor for rotating the platen, an array of half-cylinder antenna elements mounted to the platen, an elevation drive motor for pivoting the antenna elements individually about their axes to change the elevation at which the antenna elements are pointing, and a cover. The azimuth drive motor and the elevation drive motor together allow the array of antenna elements to be pointed at a satellite over a wide range of vehicle orientations.

Abstract: The invention relates to webs or batts including polytrimethylene terephthalate crimped staple fibers and fiberfill products comprising such webs and batts, as well as the processes of making the staple fibers, webs, batts and fiberfill products. According to the preferred process of making a web or batt, polytrimethylene terephthalate staple fibers, containing polytrimethylene terephthalate is melt spun at a temperature of 245-285° C. into filaments. The filaments are quenched, drawn and mechanically crimped to a crimp level of 8-30 crimps per inch (3-12 crimps/cm). The crimped filaments are relaxed at a temperature of 50-130° C. and then cut into staple fibers having a length of about 0.2-6 inches (about 0.5-about 15 cm). A web is formed by garnetting or carding the staple fibers and is optionally cross-lapped to form a batt. A fiberfill product is prepared with the web or batt.

Abstract: Poly(trimethylene terephthalate) tetrachannel cross-section staple fibers, as well as yarns, fiberfill webs, batts and products, and fabrics made therewith. Also, the process of making such staple fibers, yarns, fiberfill webs, batts and products, and fabrics.

Abstract: A phased array antenna system operative to broadcast multiple beams that each include coded data for specific users located within the coverage area of the corresponding beam. An appropriate receiver then receives and decodes a particular beam to extract the specific data for a corresponding user. Multiple users may be assigned to each beam using frequency division or orthogonal code multiplexing, and the user data may be encoded into the beams using frequency shift key or phase shift key encoding. For each coding technique, the encoded antenna control signals are combined into a total gain and total phase shift control signal, which drives a single phase and gain control device for each antenna element. In addition, a single data modulator generates the coding parameters for the entire communication system.

Abstract: A phased array antenna system that is operative to simultaneously form multiple beams without requiring an undue amount of hardware. The system collects propagating energy with a number of antenna elements to form multiple beams, encodes the beams as the energy is collected, combines the encoded beams, and then decodes the combined signal to separate the beams. In this way, the beams can be formed with a single set of antenna hardware instead of requiring a multiplicity of antenna hardware, one for each beam. Frequency coding may be implemented by repeatedly applying a Doppler phase shift to each beam, and then using a Doppler filter to separate the beams. Alternatively, a code division multiplexing technique may be implemented by using a CDMA code generator to apply a code to each beam, and then using a CDMA filter to separate the beams.

Abstract: A satellite communications system having ground user terminals, hubs, and a geosynchronous satellite. The satellite generates a network of spot beam coverage areas on the earth. A hub and at least one ground terminal are located in each of at least two spot beams. A first user terminal transmits an uplink signal according to a first signal protocol to the hub through the satellite. A second user terminal receives a downlink signal according to a second signal protocol through the downlink spot beam from the hub through the satellite. The hub may be located in the same spot beam coverage area as the first or the second user terminal or may be located in an altogether different spot beam coverage area.

Abstract: A stable partially oriented poly(trimethylene terephthalate) yarn suitable for use in subsequent drawing and/or draw-texturing operations characterized by an elongation to break of at least 110%, and a process for false-twist texturing a partially oriented poly(trimethylene terephthalate) yarn are disclosed.

Abstract: A process of making polytrimethylene terephthalate staple fibers, including (a) providing polytrimethylene terephthalate, (b) melt spinning the melted polytrimethylene terephthalate at a temperature of 245-285° C. into filaments, (c) quenching the filaments, (d) drawing the quenched filaments, (e) crimping the drawn filaments using a mechanical crimper at a crimp level of 8-30 crimps per inch (3-12 crimps/cm), (f) relaxing the crimped filaments at a temperature of 50-120° C., and (g) cutting the relaxed filaments into staple fibers having a length of about 0.2-6 inches (about 0.5-about 15 cm), and polytrimethylene terephthalate staple fibers, yarns and fabrics. Further, a process of optimizing the crimp take-up of a polytrimethylene terephthalate staple fiber including determining the relationship between denier and crimp take-up and manufacturing staple fibers having a denier selected based upon that determination.

Abstract: A satellite communications system having ground user terminals, hubs, and a geosynchronous satellite. The satellite generates a network of spot beam coverage areas on the earth. A hub and at least one ground terminal are located in each of at least two spot beams. A first user terminal transmits an uplink signal according to a first signal protocol to the hub through the satellite. A second user terminal receives a downlink signal according to a second signal protocol through the downlink spot beam from the hub through the satellite. The hub may be located in the same spot beam coverage area as the first or the second user terminal or may be located in an altogether different spot beam coverage area.

Abstract: Processes for making poly(trimethyelene terephthalate) yarn are provided. The process includes extruding a polyester polymer through a spinneret to form non-round filaments at a spinning speed less than 4500 mpm and a temperature between about 255° C. and about 275° C. The polyester polymer composition includes at least 85 mole percent poly(trimethylene terephthalate) wherein at least 85 mole percent of the repeating units consist of trimethylene units, and the polyester polymer has an intrinsic viscosity of at least 0.70 dl/g.

Abstract: A stable partially oriented poly(trimethylene terephthalate) yarn suitable for use in subsequent drawing and/or draw-texturing operations characterized by an elongation to break of at least 110%, and a process for false-twist texturing a partially oriented poly(trimethylene terephthalate) yarn are disclosed.

Abstract: Fine denier poly(trimethylene terephthalate) feed yarns and drawn yarns wherein the drawn yarns are characterized by a denier per filament less than 1.5 and are drawn such that the actual draw ratio is within 10 percent of the predicted draw ratio determined according to: [(elongation to break of the feed yarn)+115]/[(elongation to break of the drawn yarn)+115)].

Abstract: The invention provides a bicomponent fiber comprising poly(ethylene terephthalate) and poly(trimethylene terephthalate) and having: a weight ratio of poly(ethylene terephthalate) to poly(trimethylene terephthalate) of at least about 30:70 and no more than about 70:30, a scalloped oval cross-section selected from the group consisting of side-by-side and eccentric sheath-core; a cross-section long axis; a boundary between the poly(ethylene terephthalate) and the poly(trimethylene terephthalate) that is substantially parallel to the cross-section long axis; and a plurality of longitudinal grooves.

Abstract: A continuous process for the production of poly(trimethylene terephthalate) is disclosed. According to the process, a liquid feed mixture comprising bis-3-hydroxypropyl terephthalate and/or low molecular weight polyesters of 1,3-propanediol and terephthalic acid, the liquid feed mixture-having a mole ratio of propylene groups to terephthalate groups of 1.1 to 2.2 is fed to a flasher. A first stream of gaseous by-products is continuously vaporized and removed from the flasher, and a liquid flasher reaction product having a mole ratio of propylene groups to terephthalate groups of less than about 1.5 is continuously withdrawn from the flasher. The liquid flasher reaction product is continuously fed to a prepolymerizer where it is continuously polymerized to form a poly(trimethylene terephthalate) prepolymer and a second stream of gaseous by-products.

Abstract: A ground-based antenna for use with a satellite communications (SATCOM) system that reduces interference from geosynchronous earth orbit (GEO) satellites. Because GEO satellites that provide coverage of the continental United States (CONUS) are uniformly separated along an equatorial arc around the earth, the GEO satellites are approximately uniformly separated in sine space when viewed from a ground terminal located within CONUS over typical communications frequency bands, such as the Ka band (29-39 GHz) and the Ku band (10-15 GHz). The invention can reduce interference by providing an uniformly illuminated rectangular aperture, in which the horizontal dimension is chosen so when the aperture is normal to a transmission axis between the antenna and the Nth satellite of a SATCOM systems, the nulls of the antenna radiation pattern align with the N±1, N±2, N±3, . . . satellites.